It’s fair to say that thus far in his major league career, Danny Jansen has been something of a disappointment at the plate. Among 51 catchers who’ve recorded at least 250PA since the beginning of the 2019 season (i.e. over the time he’s been the primary starter in Toronto), his 74 wRC+ ranks 41st. He still ranks a solid 19th among that group in WAR, due to his unexpectedly excellent defensive grades, but Jays fans had reason to expect a little more from the guy who torched the international league to the tune of a 151wRC+ between 2017 and 2018.
Looking at his offensive production in a little more detail, there are some pretty encouraging signs. His walk rate was a respectable 8.1% in 2018, and jumped to an excellent 14.3% in 2020, supported by chase rates well below the MLB average (he swung at 25.2% of pitches outside the zone this year, compared to an MLB average of 30.6%) but above average aggression inside the zone (he swung at 73.5% of strikes, MLB average 67.8%). He also makes enough contact to get by. His strikeout rate was roughly 21% in both seasons, which is at or a little better than average. Where he’s really had problems is when the puts the ball in play. Over the course of the last two years, Jansen’s .221 batting average on balls in play ranks 9th from the bottom among all 378 hitters who meet the 250PA threshold. When Jansen does hit the ball, it finds fielder’s gloves with pretty remarkable regularity.
What’s fueling that low BABIP? The first suspect with hitters who run low BABIPS is always pop-up rates. Infield flies almost never go for hits, so hitters who create a lot of them have a drag on their batting average almost as significant as if they had a strikeout problem. Several of Jansen’s companions at the bottom of the BABIP list are all or nothing sluggers like Derek Dietrich, Gary Sanchez, and Edwin Encarnacion who sell out for pulled fly balls, trading more home runs for more pop flies. That doesn’t really seem to be the case for Jansen. His 11.7% infield fly ball rate is above the 9.6% league average, but far below the outliers at 15%+.
Another candidate is pull rate. Pulling the ball is largely a good thing for power hitters, because balls pulled in the air are responsible for most home runs. It can have a cost, though, in that a reliable pull tendency allows defenses to shift. Guys who run very high BABIPs over long careers, like Christian Yelich, Mike Trout, or Joey Votto, tend to spray the ball and use the middle of the field a lot, while guys who try to pull everything can gain in home runs but pay in lost singles. This can be a smart trade (it’s basically what redefine Jose Bautista’s career), but a low BABIP is the price. Jansen was a very pull oriented hitter in 2018 and 2019. His 53.7% pull rate in the latter year was sixth among all hitters with at least 200 PA. He changes that pattern completely in 2020, though, pulling the ball only 33% of the time (in the bottom fifth of the league). If too much pull was the problem, going the other way didn’t solve it.
The last high-level thing to look at is how hard the ball is being hit. This is pretty straightforward: hard hit balls are more likely to get to holes before a fielder can fill them. Jansen’s average exit velocities have been pretty low. In 2019, his 88.9mph average was in the 40th percentile of the league. In 2020, that fall to 85.1mph, in the 5th percentile. His hard-hit rate, though (defined as the percentage of batted balls over 95mph, which are responsible for most hits and almost all extra base hits), was in about the 62nd percentile in both seasons. While Jansen makes a lot of very soft contact, dragging his average down, he also makes really good contact at an above average rate. The low average probably indicates some issues, but as long as he’s making a lot of good contact the relatively frequent weak contact shouldn’t be killing him.
There’s no obvious culprit here. He could stand to hit fewer soft balls, and probably to pop up a little less, but overall, we have an extreme result (BABIP in the 3rd percentile) without apparently extreme average underlying traits. That prompted me to try to look a little deeper into Jansen’s batted balls, to see exactly which kinds of balls he hits more or less often than typical hitters, and on which kinds he’s having more or less than average luck.
The graph below shows the batting average of all major league hitters in the 2019 and 2020 seasons, broken down by how hard the ball was hit and at what angle. Balls are divided into increments of 10 degrees and 5 miles per hour. The size of the dot indicates how common that batted ball type was, and the colour shows how likely it was to go for a hit (this is not strictly BABIP, as home runs are counted). Basically, balls hit at between 5 and 25 degrees (i.e. line drives) usually go for hits. Balls below 5 but above -15 have a decent chance if they’re hit hard, and balls from 25 to 45 degrees can either fall in at around 70mph (bloops that drop behind the infield) or leave the yard at 95mph plus. Anything else (weak grounders, medium flies, anything hit straight down or straight up) isn’t likely to work out well for the hitter.
Next, let’s look at just Danny Jansen’s balls in play:
Looking at the size and location of the dots in Jansen’s plot, a couple things stand out: he doesn’t hit a lot of grounders, especially ones at very negative angles driven right into the dirt, and he hits a lot of medium fly balls (around 40 degrees launch angle). The former is a good thing, as almost no one produces on balls hit at -20 degrees or below. When Jansen does hit it on the ground, it’s frequently close to level (a lot of balls at 0 or -10 degrees) and in the 90-110mph band where balls can get through the infield. The latter isn’t, at least for him. Medium fly balls can be pretty productive for power hitters (note the bright red dots beyond 110mph on the league chart), but Jansen just doesn’t seem to be strong enough to do damage on balls with that kind of launch angle. He hits a lot of 90-100mph medium angle flies that probably make the outfielders go back but don’t have much chance to leave the yard or fall in for doubles.
It also appears that luck also has something to do with Jansen’s struggles. He’s had pretty bad luck on those hard ground balls, especially those hit level between 90 and 100mph and those hit around -10 degrees and over 100mph. MLB hits about .380 and .300 on those two types of balls, but Jansen is 1 for 12 and 0 for 8, respectively. There’s another big blue dot at 20 degrees between 95 and 100 mph. Those are high line drives or low flies that can get over outfielder’s heads or into the gaps and go for extra bases pretty regularly. The league hit .472 on them, while Jansen was 3 for 12. He’s also had some bad luck on soft liners (20 degrees, exit velocities in the 80s) which has cost him four or five bloop singles over the past couple years. He’s had some good luck in a few places too, but looking at his actual vs expected hits using StatCast’s xBA model, on balance he’s short about 21 hits over the last two seasons. Just getting those back would raise his average over that period from .201 to .242. That might be a little generous, since some of those lost hits might be due to shifts on his ground balls and other things beyond launch angle and exit velocity, but a significant portion of his struggles look like bad luck more than bad process.
It looks like Jansen’s poor results on balls in play are probably a combination of an approach that doesn’t ideally fit his skillset (hitting a lot of flies he isn’t strong enough to drive out of the park) and, probably more importantly, bad luck on some types of balls that are very productive for most hitters.
The last thing I wanted to do was to see which other hitters strike the ball in a similar way, to figure out how much we should expect his results to change. To do that, I assigned every batted ball from the 2017 through 2020 seasons a z score relative to league average for launch angle, exit velocity, and spray angle (the horizontal angle at which the ball travels, with -45 degrees being down the line to the hitter’s pull side and 0 being up the middle). Z scores reflect how many standard deviations above or below average a measurement is. For example, league average exit velocity was 88.5mph, with a standard deviation of 27.5, so a ball hit at 100mph has a z score of (100-88.5)/27.5 = 0.42. I, for each hitter, I calculate their 20th, 40th, 50th, 60th, and 80th percentile z scores for launch angle, spray angle, and exit velocity. This gives me a set of 15 measurements that describe the shape of the distribution of a hitter’s batted balls. To compare them to Jansen’s results, I took the square root of the sum of the squared differences between each hitter and Jansen. The lowest scores indicate the hitters least different from Danny Jansen.
The ten hitters with batted ball characteristics most similar to Jansen’s over the past two years (minimum 100 batted balls combines) are:
Hitters with Batted Ball Profiles Similar to Danny Jansen’s
That’s a pretty good list! Six of the ten are excellent hitters, and at least a couple of the ones who aren’t have major strikeout problems that Jansen doesn’t. The group’s average strikeout and walk rates are essentially the same as Jansen’s, but their average was 62 points higher on the strength of a BABIP 75 points higher. That’s cause for optimism. Hitters who strike the ball about the same way Jansen does, with similar contact and plate discipline skills, are usually very productive hitters.
Jansen has some potential areas for improvement. Cutting down on high fly balls would be good if he can do it, as would adding any additional power. The overall picture should be pretty comforting for the Jays, though. If Jansen is the starter this year and repeats the same process at the plate he has over the last couple seasons, there’s reason to believe the results will be a lot better.